End-to-end Celo development playbook (Feb 2026). Prefer viem for all client/transaction code (native fee currency support via CIP-64). Use thirdweb for wallet connection and React dApps. Foundry for smart contract development. Covers fee abstraction (pay gas in USDC/USDT/USDm), MiniPay Mini Apps, stablecoin integration, and AI agent infrastructure (ERC-8004 trust + x402 payments).